dist: Support strftime-style date formatting in log_filename

Fixes #1103

direct/src/dist/FreezeTool.py

@@ -1735,7 +1735,7 @@ class Freezer:
         return target
 
     def generateRuntimeFromStub(self, target, stub_file, use_console, fields={},
-                                log_append=False):
+                                log_append=False, log_filename_strftime=False):
         self.__replacePaths()
 
         # We must have a __main__ module to make an exe file.
@@ -1906,9 +1906,12 @@ class Freezer:
             # A null entry marks the end of the module table.
             blob += struct.pack(entry_layout, 0, 0, 0)
 
+            # These flags should match the enum in deploy-stub.c
             flags = 0
             if log_append:
                 flags |= 1
+            if log_filename_strftime:
+                flags |= 2
 
             # Compose the header we will be writing to the stub, to tell it
             # where to find the module data blob, as well as other variables.

direct/src/dist/commands.py

@@ -247,6 +247,7 @@ class build_apps(setuptools.Command):
         self.extra_prc_data = ''
         self.default_prc_dir = None
         self.log_filename = None
+        self.log_filename_strftime = False
         self.log_append = False
         self.requirements_path = os.path.join(os.getcwd(), 'requirements.txt')
         self.use_optimized_wheels = True
@@ -786,7 +787,7 @@ class build_apps(setuptools.Command):
                 'prc_executable_args_envvar': None,
                 'main_dir': None,
                 'log_filename': self.expand_path(self.log_filename, platform),
-            }, self.log_append)
+            }, self.log_append, self.log_filename_strftime)
             stub_file.close()
 
             if temp_file:

pandatool/src/deploy-stub/deploy-stub.c

@@ -39,6 +39,7 @@
 /* Stored in the flags field of the blobinfo structure below. */
 enum Flags {
   F_log_append = 1,
+  F_log_filename_strftime = 2,
 };
 
 /* Define an exposed symbol where we store the offset to the module data. */
@@ -786,6 +787,14 @@ int main(int argc, char *argv[]) {
   }
 
   if (log_filename != NULL) {
+    char log_filename_buf[PATH_MAX];
+    if (blobinfo.flags & F_log_filename_strftime) {
+      log_filename_buf[0] = 0;
+      time_t now = time(NULL);
+      if (strftime(log_filename_buf, sizeof(log_filename_buf), log_filename, localtime(&now)) > 0) {
+        log_filename = &log_filename_buf;
+      }
+    }
     setup_logging(log_filename, (blobinfo.flags & F_log_append) != 0);
   }